1. Field
The presently disclosed subject matter relates to intraluminal balloon catheters for use in percutaneous transluminal coronary angioplasty (PTCA) or stent delivery systems or the like. Particularly, the disclosed subject matter relates to a balloon catheter and system having an improved distal tip.
2. Description of Related Art
Intraluminal balloon catheters are well known and beneficial for a variety of medical uses, including diagnostics, therapeutics, and treatment. For example, and not limitation, balloon catheters can be used for a number of different vascular and/or coronary applications. In percutaneous transluminal coronary angioplasty (PTCA) procedures, a guidewire is typically advanced into the coronary artery until the distal end of the guidewire crosses a lesion to be dilated. A dilatation catheter having an inflatable balloon on the distal portion thereof is advanced into the coronary anatomy over the guidewire until the balloon of the dilatation catheter is properly positioned across the lesion. Once properly positioned, the dilatation balloon is inflated with inflation fluid one or more times to a predetermined size to open up the vascular passageway. Generally, the inflated diameter of the balloon is approximately the same diameter as the native diameter of the body lumen being dilated so as to complete the dilatation, but not over-expand the artery wall. After the balloon is finally deflated, blood flow resumes through the dilated artery and the dilatation catheter and the guidewire can be removed therefrom.
In addition to or as an alternative of angioplasty procedures, it may be desirable to implant an intravascular prosthesis, generally called a stent, inside the artery at the site of the lesion. Stents may also be used to repair vessels having an intimal flap or dissection or to generally strengthen a weakened section of a vessel or to maintain its patency. Stents are usually delivered to a desired location within a coronary artery in a contracted condition on a balloon of a catheter, which is similar or identical in many respects to a balloon angioplasty catheter. The balloon, and thus the stent, is expanded within the patient's artery to a larger diameter. The balloon is deflated to remove the catheter with the stent implanted at the site of the dilated lesion. See for example, U.S. Pat. No. 5,507,768 (Lau et al.) and U.S. Pat. No. 5,458,615 (Klemm et al.), each of which is hereby incorporated by reference in its entirety.
It is desirable to provide an intraluminal catheter with a soft distal tip to prevent or minimize injury to the vessel during advancement of the catheter therein. One challenge has been forming a connection between the soft tip and the catheter. For example, the joint or connector needs to be sufficiently strong to prevent disengagement of the soft tip, and yet prevent kinking at the junction between the soft tip and catheter shaft. Additionally, it is beneficial to balance the strength of the connection between the soft tip and the catheter shaft with the need to minimize the stiffness of the distal end of the catheter. Minimizing the stiffness of the distal end of the catheter results in improved maneuverability of the catheter.
Accordingly, there remains a need to provide a catheter with a soft tip having improved performance.